In many applications it is advantageous to have the ability to determine a position of a wireless device. Position location capabilities may be helpful for navigation, tracking, or in the event of an emergency.
Advances in the performance of portable electronics, particularly advances in the performance of processors, have added to the demand for using-position location with a variety of wireless devices.
However, position location functions can consume substantial amounts of power and, in some cases, can significantly reduce the amount of time that a wireless device can be operated on battery power. This is because the same battery typically supplies-power for positioning functions as well as for other functions such as voice and data communications.
Since the position of a wireless device can change over time, it must be updated in order to remain accurate. For example, position may change rapidly when traveling in a car or riding a motorcycle. Infrequent updates may lead to large positioning errors. This can be especially detrimental for navigation or for position location in the event of an emergency.
Therefore, it is desirable to have a position location system, method, and apparatus that can reduce the power consumed for position location functions while maintaining a level of positioning accuracy.